function imgOut = WardDownsampling(img)
%
%        imgOut = WardDownsampling(img)
%
%
%        Input:
%           -img: input image
%
%        Output:
%           -imgOut: downsampled image
% 
%     Copyright (C) 2015  Francesco Banterle
%
%     This program is free software: you can redistribute it and/or modify
%     it under the terms of the GNU General Public License as published by
%     the Free Software Foundation, either version 3 of the License, or
%     (at your option) any later version.
% 
%     This program is distributed in the hope that it will be useful,
%     but WITHOUT ANY WARRANTY; without even the implied warranty of
%     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
%     GNU General Public License for more details.
% 
%     You should have received a copy of the GNU General Public License
%     along with this program.  If not, see <http://www.gnu.org/licenses/>.
%

[n, m, ~] = size(img);
maxCoord = max([n, m]);
viewAngleWidth  = 2 * atan(m / (2 * maxCoord * 0.75));
viewAngleHeight = 2 * atan(n / (2 * maxCoord * 0.75));
fScaleX = (2 * tan(viewAngleWidth / 2) / 0.01745);
fScaleY = (2 * tan(viewAngleHeight / 2) / 0.01745);


imgOut = imresize(img, [round(fScaleY), round(fScaleX)], 'bilinear');

end